6 



THE FARMER'S MAGAZINE. 



verse principle governed the operations, the num - 

 ber of drains being increased to a maximum con- 

 sistent with economy ; the object being twofold — 

 not only to remove excess of wetness, but to pro- 

 mote an uniform aeration of the mass of clay above 

 the level of the drains, so as to counteract as much 

 as possible its absorbent and retentive nature. 



" The total net cost of draining the 800 acres 

 was £3,357 10s., giving an average cost per acre of 

 £4 4s." 



And the reporter had the satisfaction of adding 

 at the close of his valuable paper that the Clay-land 

 Farm had just been let, on terms securing a full 

 return for the capital expended m draining, and 

 other improvements. 



The recorded comparative movement of the 

 water in the mixed and the clay soils of Hinxworth 

 are certainly not the least interesting portion of 

 these observations. As might be reasonably ex- 

 pected, Mr. Denton tells us that the discharge 

 from the mixed open soils was much more regular 

 than from the clays. The quantity of water dis- 

 charged by the comparatively few drains of the 

 freest description of soil during the period of the 

 experiments was lG0,920 gallons per acre, out of 

 227,240 gallons which the rain-gauge showed fell 

 upon every acre drained, while the quantity dis- 

 charged from the numerous drains of the clays was 

 only 59,936 gallons per acre. 



The steady discharge of more than 1,000 gallons 

 per acre pef diem from the mixed open soils during 

 the winter — when evaporation is so much less than 

 during the summer — is a fact of considerable im- 

 portance, when considered in relation to the wide 

 extent of similar land requiring drainage. It will 

 be observed, too, that after the autumn rains had 

 completely replenished the absorbent demands of 

 the clays, a large proportion of any succeeding rain 

 was immediately discharged by the under-drains. 

 There was a fall of rain at Hinxworth in October, 

 1856, of 1*645, and in November of 1'630, equal 

 together to a supply to the soil of 74,087 gallons, 

 or 330 tons of water per acre. The drains just 

 began to trickle on the 27th of November, after a 

 fall of half an inch of rain ("540). The test holes 

 in the land showed that the soil was rapidly feed- 

 ing itself, and that the water-level was rising, but 

 had not reached the level of the drains. On the 

 12th December the outlets were running I60 gals, 

 per diem, per acre, after frequent rains in the early 

 part of the month, of less than a tenth of an inch 

 per diem. On the 13th the rain-gauge showed a 

 fall of -452 (nearly half an inch), and the outlets 

 increased their discharge from I60 to 975 gallons 

 per diem per acre. On the 9th January, 1857, the 

 outlets were running 125 gallons per diem. On 

 the 10th the rain-gauge showed a fall of '542 (rather 

 more than half an inch), and the discharge from 

 the outlets was increased from 125 to 5,150 gallons 

 per diem per acre. How important, adds the re- 

 porter, are these facts, in considering the effect of 

 extended underdrainage on the arterial channels of 

 the country ! 



Th» estate of Hinxworth is thus described by 

 Mr. Denton {Journal Roy. Ag. Soc, vol. xx. p. 

 273)—" It lies at the bottom of the chalk escarp- 

 ment of the London Basin, and covers a portion of 



the lower bed of chalk, the out-crop of the green- 

 sand, and a portion of the gault of the green-sand 

 formation. In several parts a superficial deposit of 

 drifted gravel and sand overlies the older beds. 

 The green-sand separating the chalk from the gault 

 is very thin, and if collected in a distinct layer, 

 would not exceed three inches in depth in its 

 thickest part. The gault has gained a siliceous 

 character where it comes immediately in contact 

 with the green-sand. It has also imbibed a cal- 

 careous quality by an infiltration of the chalk 

 through the green-sand into its bed ; for a wide 

 breadth, however, the gault is denuded, and there, 

 although the green-sand is absent, a very consider- 

 able infiltration of lime has taken place, which I 

 presume may be accounted for by the fact that the 

 chalk escarpment rises in almost cliff-like shape im- 

 mediately at the margin of the gault, and any sub- 

 mersion of the gault has necessarily imparted to it 

 the character of its more prominent and overwhelm- 

 ing neighbour. The nature of the soil is ever of 

 paramount importance in considering the results of 

 any reported drainage operations." 



The following are the analyses of the soils of 

 Hinxworth by Professor Way : — 



OF THE LOWER CHALK AND MIXED DRIFT. 



Moisture and orgaBic matter .. .. 3'27 



Sands and cliiys 24"37 



Silica soluble in acids 1*23 



Oxide of iron I'l-l 



Phosphate of lime 0'92 



Sulphate of lime 0-7G 



Carbonate of lime 08 31 



lOG'OO 



OF THE GAOLT (aT 24 INCHES DEEPj. 



Moisture and organic matter .. .. 5'01 



Sands 0-66 



Clay e3'26 



Carbonate of lime 3107 



100-00 



OF THE GAULT (AT 42 INCHES DEEP). 



Moisture and organic matter .. .. 4'28 



Sands 0-34 



Clay 02 97 



Carbonate of hme 32'41 



10000 



It is from such careful practical observations that 

 the young farmer will derive the most useful in- 

 formation as a guide to his drainage operations. It 

 is not, it is true, the landholders cf the light-soil dis- 

 tricts of our island that have to encounter the ex- 

 pense of land-drainage. The question is of jjut 

 very inferior interest to the skilful agriculturists of 

 the Norfolk sands, the Suffolk crag, and of the 

 great southern chalk formation of Surrey, Hants, 

 and Dorset; but it is of great and enduring im- 

 portance to the farmers of our extensive clay lands. 



It will, we may all very easily discern, be long 

 of increasing importance to the cultivators of such 

 retentive soils. It is to them, in fact, that we must 

 now look for "that supply of animal food needed to 

 support a rapidly increasing population ; and the 

 greater the advances are made in converting such 

 heavy-soil holdings into stock farms, the more de- 

 sirable it becomes to render their drainage more 

 complete. 



